For protection against infection by pathogens (infection prevention) and treatment of diseases such as infections and cancer, a vaccine is sometimes administered to a living body. A vaccine is usually administered with an immunostimulator. The immunostimulator is also called as an adjuvant. The immunostimulator has an ability to enhance the effect of vaccine such as enhancement of immune response to a vaccine antigen. For example, US Patent Application Publication No. 2015-174223 describes that an adjuvant can be contained in a pharmaceutical composition containing a peptide vaccine. As specific examples of adjuvant, aluminum phosphate, aluminum hydroxide and the like are described.